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This method can remove the need to add other chemicals to a distillation, but it has two potential drawbacks. Under negative pressure, power for a vacuum source is needed and the reduced boiling points of the distillates requires that the condenser be run cooler to prevent distillate vapors being lost to the vacuum source.
Distillation, widely used in petroleum refining and in purification of ethanol separates volatile liquids on the basis of their relative volatilities. There are several type of distillation: simple distillation, steam distillation etc. Water purification combines a number of methods to produce potable or drinking water.
The McCabe–Thiele method is a technique that is commonly employed in the field of chemical engineering to model the separation of two substances by a distillation column. [1] [2] [3] It uses the fact that the composition at each theoretical tray is completely determined by the mole fraction of one of the two components.
Design and operation of a distillation column depends on the feed and desired products. Given a simple, binary component feed, analytical methods such as the McCabe–Thiele method [4] [6] [7] or the Fenske equation [4] can be used. For a multi-component feed, simulation models are used both for design and operation.
Short path distillation is a popular method due to the short residence time which allows for minimal thermal stress to the concentrate. In other distillation methods such as circulation, falling film and column distillation the concentrate would be damaged from the long residence times and high temperatures that must be applied.
High purity oxygen, nitrogen, and argon, used for semiconductor device fabrication, require cryogenic distillation. Similarly, the only viable source of the rare gases neon, krypton, xenon is the distillation of air using at least two distillation columns. Helium is also recovered in advanced air separation processes. [1]
Common Equipment used in Azeotropic Distillation. This practice of adding an entrainer which forms a separate phase is a specific sub-set of (industrial) azeotropic distillation methods, or combination thereof. In some senses, adding an entrainer is similar to extractive distillation.
In practice, distillation may be carried out by either two principal methods. The first method is based on the production of vapor boiling the liquid mixture to be separated and condensing the vapors without allowing any liquid to return to the still. There is no reflux. The second method is based on the return of part of the condensate to ...